1. Field of the Invention
The present invention generally relates to the field of vehicular wheelchair lifts for persons who are physically challenged or otherwise have limited mobility. More particularly, the present invention relates to the field of vehicular wheelchair lifts with an automatic safety barrier for preventing a wheelchair from inadvertently rolling off a platform of the wheelchair lift in the boarding and exiting of a vehicle.
2. Description of the Prior Art
Vehicular wheelchair lifts are widely utilized to assist persons in wheelchairs to enter and exit vehicles. These lifts typically have a platform for transporting an occupied wheelchair, where the platform can be raised and lowered between a loading position at the ground level outside a vehicle and an entry position at the floor level inside the vehicle, and a safety barrier connected to an outer end of the platform for preventing a wheelchair from inadvertently rolling off the platform during use of the wheelchair lift.
While many of the prior art safety barriers have accomplished in minimizing the risk for injury to users of the wheelchair lifts on which they are installed, a need has developed for even greater security in this respect. Many prior art barriers currently in use are subject to the possibility that they may not always be operative by both power and manual controls. Some prior art safety barriers are not strong enough to positively assure against accident and resultant injury. These safety barriers stop to prevent objects from sliding or rolling off the lifts and are well known as disclosed in the following prior art patents below.
U.S. Pat. No. 5,556,250 issued to Fretwell et al. on Sep. 17, 1996 discloses a wheelchair lift with a power roll stop actuated by a separate motor drive mechanism. If power or the motor becomes inoperable by any reason, disassembly some linkage parts in the motor drive mechanism is a must in order to, manually open and close the roll stop.
U.S. Pat. No. 4,124,130 issued to Rohrs et al. on Nov. 7, 1978 discloses a wheelchair lift with a safety barrier. The safety barrier is not power controlled.
U.S. Pat. No. 5,040,936 issued to Rhea on Aug. 20, 1991 discloses a wheelchair lift with a foldable safety barrier. The safety barrier is not power controlled.
U.S. Pat. No. 4,556,128 issued to Thorley et al. on Dec. 3, 1985 discloses a wheelchair lift with a power safety barrier. The safety barrier is actuated by a hydraulic cylinder. If the hydraulic power or any element becomes inoperable, the safety barrier cannot be opened and closed manually.
U.S. Pat. No. 5,439,342 issued to Hall et al. on Aug. 8, 1995 discloses a platform wheelchair lift with a safety barrier actuation mechanism. The actuation mechanism is driven by a hydraulic cyliner. The barrier cannot be opened and closed manually in the event of a power failure.
U.S. Pat. No. 4,442,921 issued to Sherman on Apr. 17, 1984 discloses a wheelchair platform lift with a safety barrier. The barrier is actuated by a barrier pivotal latch mechanism without power control.
U.S. Pat. No. 5,401,135 issued to Stoen et al. on Mar. 28, 1995 discloses a wheelchair lift with a safety barrier. The barrier opens and closes by a barrier pivotal latch mechanism without power control.
It is desirable to provide a wheelchair lift with a power controlled safety barrier for facilitating the entrance and exit of persons who are physically challenged or otherwise have limited mobility into or from a vehicle which significantly improves the safety of the wheelchair lift. It is also desirable to provide a wheelchair lift with a power controlled safety barrier which eliminates risks attributable to a wheelchair inadvertently rolling off a platform of the wheelchair lift during use.